急性CO中毒大鼠脑海马区多巴胺类递质的变化特点

Change pattern of dopamine and its metab olites in hippocampus area of carbon mon oxide exposed rats

目的研究急性一氧化碳(CO)中毒大鼠脑海马多巴胺(DA)及其代谢产物二羟苯乙酸(DOPAC)、高香草酸(HVA)水平的变化特点。方法将大鼠随机分成对照组和CO中毒组,采用腹腔注射CO法染毒,首次染毒剂量为120 ml/kg,每隔4 h注射一次,剂量为60 ml/kg,共3次;对照组以同种方法和剂量注射空气。利用Morris水迷宫实验、脑组织病理学检查方法鉴定迟发性脑病组大鼠,通过在体微透析和高效液相色谱技术观察脑海马区DA及其代谢产物末次染毒后及迟发性脑病期的变化特点。结果腹腔注射CO末次染毒后,大鼠脑海马区DA水平增加,其代谢产物明显减少;4～6 h以后,随着血中CO水平下降,上述变化亦逐渐消失,11 h左右大致恢复至正常水平;与对照组比较,出现迟发性脑病的大鼠海马区DA水平再次明显增加,其代谢产物水平则再次明显降低。结论急性CO中毒及CO迟发性脑病均可见DA及其代谢产物出现异常变化,推测此种变化可能与中枢神经系统损伤症状有关,具体细节仍需进一步研究澄清。

Objective To explore the effect of carbon monoxide（CO）poisoning on the change patterns of dopamine（DA）and its m etabolites,such as dihydroxyphenylacetic acid（DOPAC）and homovanillic acid（HVA）in hippocampus area of in rats.Methods Rats were randomly divided into control grou p and CO exposed group.CO was intra-peri tonealy injected with the dose of 120 ml /kg at the first time,the repeated 3 tim es of injection CO（60 ml/kg）was subseque ntly given every four hours.10 day s later,rats were tested by Morris water maze test and pathological examination for the identification of delayed enceph alopathy.Then,the changes of DA and its metabolites in hippocampus area of the r ats were determined by means of brain mi crodialysis and HPLC.Results Compared to control group,CO exposure might signifi cantly raise the extracellular levels of DA and its metabolites,4—6 hours later, with the decline of HbCO,these changes also gradually recovered in hippocampus area; while in CO induced delayed encephalopat hy rats,same phenomenon was still observed.Conclusion The results showed that ther e was a definite change of DA and its me tabolites in hippocampus area both in acu te CO poisoned rats and in CO induced de layed encephalopathy rats,which suggeste d that these changes may be associated w ith the symptoms of central nervous syst em damage.